Amateur television

The lowest frequency ham band suitable for television transmission is 70 centimeters, which is between broadcast channels 13 and 14.

[4] As such, ATV transmissions can be viewed by setting a television or analog cable-box to cable input and attaching an outdoor antenna.

VSB-AM is where DSB-AM is filtered and the lower sideband is highly attenuated at frequencies more than 1.25 MHz from the carrier signal.

The 2 meter frequency may be used throughout the contact to talk back to the current station transmitting video.

Such receivers can decode FM television when an outdoor antenna is connected to the LNB input.

Due to the low cost and ease of repurposing old analog satellite receivers, this is the most popular band for FM amateur TV.

Commonly used 23 cm FM channels: This band is also used for AM/VSB television, although this requires a specialized receiver.

In Europe, which generally has a narrower 70 cm allocation than the USA, the majority of amateur television operation is currently frequency modulated on 1.3 GHz and above.

Simplex operation occurs on these or other frequencies chosen to avoid interference with other users of the band, e.g. 1.285 GHz.

Recent experiments have been done with digital modes following widely adopted DVB-S and DVB-T standards.

These new DATV transmissions need less spectrum bandwidth than FM-ATV and offer superior picture quality.

However, the unavoidable processing delays caused by the temporal compression mean that DATV signals have a second or more of time lag, which can make real-time video conversations feel much less natural than the 'instantaneous' analogue system.

P-0 signifies a state in which sync bars are visible, but the picture is too snowy to be seen; this occurs at a minimum signal strength of 3 dB.

Factors such as E-layer skip propagation, tropospheric enhancement, and knife-edge diffraction can extend the useful range of signals.